Dental venting device



. lan..6; 1970 '-B.WEISSMAN I 5 DENTAL VENT ING DEVICE Filed Feb. 16, 1968 F/G/ F/G. 2

INVENTOR. 6/ 4/440 A/ JMAA/ United States Patent 3,487,544 DENTAL VENTING DEVICE Bernard Weissman, 304 Ashland Place, Brooklyn, N.Y. 11217 Filed Feb. 16, 1968, Ser. No. 705,953

Int. Cl. A61c 5/08 U.S. CI. 32-12 17 Claims ABSTRACT OF THE DISCLOSURE This invention is concerned with providing means for venting crowns used in prosthetic restoration. Briefly, the invention comprises providing a threaded venting pin for engagement into an associatingly threaded aperture disposed at a desirable location in the crown. The threaded venting pin is suitably adapted with venting means such as a channel or grooves communicating to the exterior of the crown so that when the crown is seated onto the previously prepared tooth, cement filling the hollow cavity of the crown is caused to be displaced into the channel or groove until the excess thereof is spent providing for an air-tight fit when the venting means are subsequently sealed off.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to the field of prosthetic restoration generally. More particularly, the invention relates to dental venting devices for use in connection with crown work.

Description of the prior art The major portion of a tooth comprises a bonelike substance called dentin, which is covered by enamel to form the crown and by cementum to form the root. The root of a tooth is attached to the alveolar bone by fibrous connective tissue called the periodontal membrane. Within the crown and the root of a tooth is a filament of soft tissue called the pulp. The nerves and blood vessels enter and leave the pulp through an opening at or near the root end.

When a tooth has become broken or chipped, quite often it is preferable not to extract the damaged tooth since it provides support for the teeth adjacent thereto. This is also the case if the tooth has become carious and unsightly and yet can be saved from extraction. What is done is to grind away a substantial portion of the crown and then provide an artificial crown which is cemented to the remaining exposed portion of the tooth.

The artificial crown is a matched replica of the original crown except that the interior thereof is provided with a hollow cavity. Into this cavity is placed a suitable dental cement and then this replacement crown is fitted over the remaining tooth. However, this technique has several dis advantages. Air is trapped between the tooth and the crown leaving spaces uncemented. Cement is caused to fiow outside the edges of the crown and into the gums, and seating of the tooth is generally poor. It is apparent that the securement of crown to tooth can, under the aforementioned method, become a rather hit and miss affair.

SUMMARY OF THE INVENTION It is, therefore, among one of the principal objectives of this invention to provide a means for accomplishing the securement of crowns to teeth that will result in accurate crown seating and ease of application.

In accordance with the present invention, means for venting crowns have now been discovered which comprise a threaded venting pin suitably adapted to be threaded into an associatingly threaded aperture located through 3,487,544 Patented Jan. 6, 1970 the crown wall. The threaded venting pin is further suitably adapted with venting means so that when it is in place in the crown, and the crown is seated onto a previously prepared tooth, cement filling a hollow cavity in the interior of the crown is caused to be displaced upward through the said venting means, said venting means communicating to the exterior of the crown, until the excess of the cement is spent and the space between the crown and tooth is substantially air-free.

BRIEF DESCRIPTION OF THE DRAWING view showing the detached relation of the prepared tooth,

crown therefor and the venting device;

FIGURE 5 is a cross-sectional fragmentary view showing the parts of FIG. 4 in attached relationship;

FIGURE 6 is a cross-sectional fragmentary view showing the crown seated in place on the tooth with the top of the venting device sheared flushly away;

FIGURE 7 is a perspective view of another embodiment of the venting device; and

FIGURE 8 is a view taken along line 8-8 of FIG. 7

looking in the direction of the arrows located just below the numerals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures of the drawing, for purposes of illustration FIG. 1 depicts a tooth before it has been prepared by grinding for the attachment thereto of an artificial crown. It can be seen that the major portion of the tooth, as labeled, comprises a bonelike substance called dentin, which is covered by enamel to form the crown and by cementum to form the root. Within the crown and the root of the tooth is a filament of soft-tissue called the pulp. The root of the tooth is attached to the surrounding bone by means of fibrous connective tissue (not shown). The gingiva (or gum) covers the bone inside the mouth. i

FIG. 2 shows the tooth after the crown portion has been ground away by suitable grinding means well known to'the dental art leaving some enamel along the gum line. Thereafter a crown is prepared by conventional means also well known to the art. A threaded aperture 10 is pro vided through the wall of the crown 12 (FIGURE .4) at 7 a front tooth is to be crowned then the lingual surface (i.e. facing the tongue) would be provided with the;

threaded aperture 14. The threading of aperture 10 may be accomplished by preferably boring a pin hole after the crown is waxed, in the wax pattern on the die, selecting the most desirable area. The pattern is removed from the die and a threaded pin (nickel or silver) is inserted into the pin hole, allowing it to protrude from either side of the wax pattern and sealed from the outside securely into place. After the casting is cut off from the sprue, the pin is removed by suiable means, such as dissolving with nitric acid, leaving an internally threaded aperture in the casting.

Alternatively, the internally threaded aperture may be made after the crown has been cast by conventional threading means, but this is less preferred.

A venting device 20 with externally threaded walls 22, in associated threading relation with aperture 14 is provided for threading insertion into aperture 14. The venting device 20 (FIG. 3) comprises a generally cylindrically shaped body 24 with the upper portion 26, upper with respect to the outside surface of the crown 12, being slightly inwardly tapered, and terminating after said tapered portion with a shank 28 integrally connected therewith. Said shank 28 has a base 30 substantially parallel to the base 32 of the cylindrical body 24, but preferably Wider than the diameter of the said cylinder. Integrally connected to base 32 are two inwardly converging sides 34 and 36 which merge into said tapered portion 26 of body 24. In cross-section, said shank 28, looking at FIGS. 4 and 5, resembles an inverted triangle, preferably equiangular, with the bottom portion being truncated. As mentioned, the body portion 24 is externally threaded as at 22, which threading preferably terminates at the beginning of the tapered portion 26. A channel 40 bisects the cylindrical body 24. The length of the channel 40 is adapted to be slightly longer than the length of aperture 10, so that when the venting device 20 is threaded into the aperture 14 by means of threaded walls 22 the crown 12 will be resultingly vented. The threading of walls 22 continues for several turns past the termination of channel 40 at its venting end 42 for a reason to be subsequently set forth. The venting device 20 is cast of preferably stainless steel and preferably gold plated, although any suitable metal may be utilized.

Describing now the operation of the device of the invention, reference may be had to FIGS. 3-6. The venting device 20 is threaded into aperture so that the venting end 42 of the device remains exposed to the air. Thereafter a dental cement 44 conventionally known to the art is placed in the interior cavity 46 of the crown 12 substantially filling said cavity. Following this the crown 12 is immediately placed over the prepared tooth and the crown 12 is forced down onto the tooth in the direction of the arrow in FIG. 4, or upwards as the case may be. When the crown 12 is forced over the tooth, the cement 44, substantially filling the interior cavity 46 thereof, is caused to be displaced upwardly through the channel 40 in the direction of the arrows as shown in FIG. 5, and exiting from the venting end 42 of the said channel 40, until the excess amount of cement is spent. Thereafter the device 20 is threaded several more turns by means of shank 28 into the aperture 10 until the venting end 42 of the channel 40 is sealed otf achieving an air-tight seal thereby. The device is threaded by means of a latching wrench or suitable drive mechanism. When the final turns have been made, as described, the protruding shank 28 is cut off with a cutting device such as a small rotary disc, then finished and polished smooth with the contour of the crown (FIG. 6). The venting end 42 is now below the exterior surface of the crown, Alternatively, instead of a shank, the venting device may be provided with an Allen type head, such as is found on an Allen screw, and this modified venting device may be secured to the tooth by means of an Allen wrench. The Allen head may be adapted to proceed into a smooth relation with the crown surface, or it may be adapted to be cut off as is shank 28 above. Still further, it is to be understood that aperture 10 may proceed partially into the dentin layer of the tooth so that an even more secure attachment of crown to tooth is achieved by the invention venting device.

The advantages achieved by using the novel venting device are manifold: (a) the cement and trapped air are allowed to escape through the venting channel permitting the casting to seat fully; (b) accurate marginal seating is achieved between crown and tooth; (c) there is no elevation of the crown caused by cement and air trapping, and (d) there is no occlusal interference after permanent seating with the cement.

While as described the device 20 was placed in the crown before the start of the crowning operation, it is to be understood that the venting device can also be placed immediately after the crown has been seated. The venting device may also serve as a set screw for additional retention against the dentin. After the casting is seated, a drill is used through the aperture 10 to provide an indent in the dentin, more cement is forced into the aperture and thereafter the venting device is threaded back into the aperture, acting as before, and finally securing itself in the indent in the dentin. Thus the solid understructure is fully engaged creating a set lock that opposes unseating forces.

In FIGS. 7 and 8 there is shown a still further embodiment of the invention. The device 20- has threaded walls 22 as before and has a shank 28; however, cylindrically shaped body 24 is provided with parallel oppositely disposed grooves 50 and 52 cut into its vertical threaded walls 22. As shown in FIG. 7, the grooves are seen to be cut at substantially right angles to the vertical, however it is clear that the grooves can also be V-shaped as well. Said grooves 50 and 52 are placed in the same relation as channel 40 in said device, and function in the same manner as channel 40. Of course while a pair of grooves are preferred, a single groove would also be satisfactory, especially a V-shaped groove.

While the venting device is shown as preferably having a tapered upper portion 26, to facilitate in the removal of the shank 28, it is to be understood that this is not essential and the body portion 24 may be cylindrically shaped for its entire length until it merges with said shank 28. It is also to be understood that the threading on the body of the threaded wall 22 need not extend the entire vertical length of body 24 but need only extend beyond the terminus point of channel 40 or grooves 50 and 52 for several turns or more. It is further to be understood the inventive device and method work easily as well where the tooth is ground almost to the gum line and an anchor peg is inserted into the stump over which the crown 1s cemented.

Having thus described the invention with regard to specific embodiments thereof, it is understoodthat various changes may be made by those skilled 1n the art without departing from the spirit and scope thereof.

I claim:

1. In combination a dental crown and venting device therefor comprising an at least partially threaded body integrally connected at one end thereof with a smooth shank portion, said partially threaded body adapted to be engaged with associatingly threaded openlng means (118- posed in a wall of said crown, said crownbeing provided with an interior hollow cavity for contalnlng cementing means therefor, said threaded body being further provided with venting means so that when said threaded body is threadingly engaged in said opening means and said crown is seated onto a tooth prepared therefor, cement means substantially occupying said interior cavlty of said crown are caused to be displaced into and through said venting means, said venting means communicatmg to the exterior of said crown, until the excess portlon of said cementing means is spent.

2. A combination according to claim 1, wherein after said excess portion of said cementing means is spent, said venting means are sealed off.

3. In combination a dental crown and venting device therefor comprising an at least partially threaded body adapted to be engaged with associatingly threaded opening means disposed in a wall of said CI0WI1, S211d crown being provided with an interior hollow cavity for containing cementing means therefor, said threaded body being further provided with venting means so that when said threaded body is threadingly engaged in said opening means and said crown is seated onto a tooth prepared therefor, cement means substantially occupying said interior cavity of said crown are caused to be displaced into and through said venting means, said venting means communicating to the exterior of said crown, until the excess portion of said cementing means is spent and wherein said threaded body comprises a substantially cylindrically shaped body inwardly tapered at one end thereof, and having integrally connected therewith at said tapered end a shank portion, said cylindrically shaped body being threaded at least partially along its vertical length, said venting means provided on said threaded body comprising a channel member bisecting said cylindrical body for at least a vertical portion thereof, the length of said channel being slightly longer than the depth of said threaded opening means comprising a threaded aperture, the threading on said cylindrical body extending beyond the termlnus point of said channel.

4. A combination according to claim 3, wherein after said displaced portion of said cement means is spent said venting means are sealed off by threaded said body further into said threaded aperture until said channel member is below the external surface of said wall of said crown.

5. In combination a dental crown and venting device therefor comprising an at least partially threaded body adapted to be engaged with associatingly threaded open ng means disposed in a wall of said crown, said crown being provided with an interior hollow cavity for containing cementing means therefor, said threaded body being further provided with venting means so that when said threaded body is threadingly engaged in said opening means and said crown is seated onto a tooth prepared therefor, cement means substantially occupying said interior cavity of said crown are caused to be displaced into and through said venting means, said venting means communicating to the exterior of said crown, until the excess portion of said cementing means is spent and wherein said threaded body comprises a substantially cylindrically shaped body having integrally connected therewith at one end thereof a shank portion, said cylindrically shaped body being threaded at least a portion of its vertical length, said venting means provided on said threaded body comprising a pair of oppositely disposed grooves located along the vertical length of said cylindrical body and terminating below the terminus point of said threading.

6. A venting device for a dental crown adapted to receive said device comprising a substantially cylindrically shaped body inwardly tapered at one end thereof, and having a shank portion integrally connected therewith at said tapered end, said cylindrical shaped body being threaded at least partially along its vertical wall, said cylindrical body being provided with venting means comprising a channel member bisecting said cylindrical body for at least a vertical portion thereof, the threading on said cylindrical body extending beyond the terminus point of said channel, said device being receivable in associatingly threaded opening means provided in a wall of said dental crown.

7. A venting device according to claim 6, wherein said venting means comprise a pair of oppositely disposed grooves located at least partially along the vertical length of said cylindrical body and terminating below the terminus point of said threading.

8. A device according to claim 6, wherein said threading terminates at the beginning of said tapered end.

9. A device according to claim 6, wherein said venting device is formed of stainless steel.

10. A device according to claim 7, wherein said venting device is formed of stainless steel.

11. A combination according to claim 3, wherein said threading of said cylindrical body extends substantially up to the beginning of said tapered end.

12. A method for venting and sealing a dental crown which comprises providing a threaded body adapted to be secured to associatingly threaded opening means disposed in a wall of said crown, said threaded body being provided with venting means, said crown being provided with an internal hollow cavity for containing cementing means therefor, so that when said threaded body is threadingly engaged in said opening means and said crown is seated onto a tooth prepared therefor, cementing means substantially occupying said internal cavity of said crown will be caused to be displaced into and through said venting means, said venting means communicating to the exterior of said crown, until the excess portion of said cementing means is spent, and thereafter sealing off said venting means.

13. A method according to claim 12, wherein said threaded body is threadingly engaged in said opening means after said crown is seated on said tooth.

14. A method according to claim 13, wherein said threaded body is further threadingly engaged into a wall of said tooth provided with an indent therefor.

15. A venting device according to claim 6, wherein said venting means comprises a V-shaped groove extending along the vertical dimension of said cylindrical body and terminating below the terminus point of said threading.

16. A venting device according to claim 5, wherein said shank is shaped substantially as a truncated triangle with the base of said triangle being wider than the diameter of said cylindrical body, and the truncated portion thereof merging integrally with said body.

17. A venting device according to claim 1, wherein said threaded body is provided with an Allen-type head.

References Cited UNITED STATES PATENTS 336,231 2/1886 Grout 3213 838,849 12/1906 Davis 32-13 2,784,865 3/1957 Rieke 215-56 XR ROBERT PESHOCK, Primary Examiner 

